President Obama has officially asked Congress for the powers to wage war against ISIS, including "limited" ground combat operations.

But there is disturbing new intelligence that could make fighting the brutal terror group even tougher.

The National Counterterrorism Center (NCTC) estimates that more than 20,000 foreign fighters have already joined ISIS in Syria, coming from 90 countries and including more than 3,400 from Western nations and 150 from the U.S.

John Huddy reported on "Happening Now" that there has been growing concern and debate that the coalition airstrikes are not enough to take out ISIS forces on the ground.

Huddy said the number of foreign militants flocking to ISIS is growing at an "unprecedented rate" compared to the numbers who went to Afghanistan, Iraq, Yemen among other countries during the last 20 years.

"Right now, U.S. ground forces are involved in a non-combat role in the training, advising and assisting of Iraqi troops on the ground," Huddy said. "All of this continues a debate about how much of a role the United States should play in fighting ISIS, not only from the air, but also on the ground."

Watch the clip above.